Final drive structure for crawler tractors



Aug. 13, 194,6. w. o. BECHMAN ET AL 2,405,549

FINAL DRIVE STRUCTURE FOR CRAWLER TRAcToRs Filed June 26, 1944 2 Sheets-Sheet l Aug. 13, 1946. w. o. BECHMAN ET AL. 2,405,549

FINAL DRIVE STRUCTURE FOR CRAWLER TRACTOBS Filed June 26, 1944 y v 2 SheetS-Sheet' Patented Aug. 13, 1946 UNITED STATES PATENT GFFICE FINAL BREVE STRUCTURE FOR CRAWLER TRACTORS New `lersey Application June 26, 1944, Serial No. 542,142

(Cl. i4-606) 3 Claims.

This invention has to do with a drive structure for a crawler tractor and more particularly relates to a multi-compartment frame housing of the tractor together with journaled supporting means therein for a steering clutch, and drive and driven members for the clutch which are detachably associated therewith in such a manner that the clutch @an be relatively easily installed and removed in a clutch receiving compartment of the frame housing without the necessity of removing or detaching unassociated parts.

Attention is invited to U. S. Patent No, 2,197,289 to D. B. Baker et al., which shows a track drive for a crawler tractor wherein the design is such that the steering clutches can be removed from their housing compartments in a manner minimizing the number of operations and time with respect to what had been required theretofore, but the present invention makes it possible to further diminish the time and effort required in the removal, repair, and reinstallation of a clutch. Attention is also directed to copending applica.- tions Serial Nos. 542,143, 542,144, and 542,i l5, all filed June 26, 1944, assigned to the assignee of the present application and claiming subject matter herein shown but not claimed.

In conventional track-laying tractors, steering is accomplished by the interruption of the driving force to one of the vehicle tracks. Interruption of the driving force is brought about selectivel)T to either of the tracks by the opening of a steering (and power transmitting) clutch which is interposed in the power delivery train leading spectively thereto. in larger tractors the steering clutches are the multiple disk type and are both large and heavy, requiring a hoist for their support during an installation or removal operation. Moreover, the severe service to which the tractors are subjected makes it necessary for the frequent service of the clutches. It is desirable, therefore, to provide a clutch installation which will minimize the task of removing and reassembling the clutches and this invention accomplishes such object by so constructing the power transmitting element-s and the parts of the tractor collateral thereto that these collateral parts need no be disturbed when the clutch is withdrawn or installed.

Another object is the provision in a frame housing for a crawler tractor of a. lubricant-free clutch compartment between lubricant-containing compartments, power transmitting shafting extending from a clutch in the clutch compartment into the lubricant-containing compartments in conjunction with sealing means which provides 2 for the manipulation of such shafting, pursuant to removal of the clutch, without attendant leakage oi lubricant into the clutch compartment.

A further object is the provision of a driving assembly according to the preceding object, wherein one of the shafts is axially movable from the clutch after its disconnection therefrom to provide necessary clearance for removal of the clutch.

Still a further object is the provision of a novel tubular driving member journaled upon opposite walls of one of the lubricant-containing compartments, sealing means cooperable with said tubular member for preventing accidental leakage of the lubricant through shaft openings in each of said walls, and wherein the driving shafts for clutches upon either side of said compartment project through said openings into axially adjustable driving relation with the tubular member to facilitate axial movement of each of said shafts away from its respective clutch after detachment therefrom, to p-rovide the aforesaid clearance which facilitates the clutch removal.

These and other desirable objects inherent in and encompassed by the invention will be better understood after reading the following description with reference to the accompanying two sheets of drawings, wherein:

Fig. 1 is a horizontal sectional view taken through the rear portion of the body or frame housing of a crawler tractor, showing a center gear compartment, a clutch compartment, and a portion of a final drive compartment;

Fig. 2 is a vertical sectional view of the apparatus shown in Fig. l, but with the clutch viewed in elevation and illustrated in a partly removed position; and

Fig. 3 is a sectional View taken on the line 3--3 of Fig. 2.

With continued reference to the drawings, the rear body of the tractor, which may be considered as the tractor frame and also as a housing for the power transmission mechanism, is shown only suiciently to disclose the relation of such mechanism to a power input shaft It and a power output shaft ll. The frame housing l2 includes a change speed transmission gear compartment I3, wherein gearing (not shown) determines the speed and direction that the input shaft lil is driven with respect to the vehicle engine. There is also provided in the frame housing l2 a gear compartment it, clutch compartments l5 on opposite sides of said gear compartment and nal drive compartments iS (only one being shown) outwardly of the clutch compartments l5. A tail wall I'I separates each of the compartments I5 from its associated final drive housing I6, and a e head wall I8 separates the gear compartment I4 from each of the clutch compartments I5.

Power fromthe input shaft I9 is transmitted through a pinion gear I 9 formed integrally therewith to a bevel gear 2l and Athence to a tubular driving member 22, having a flange 23 to which the gear 2| is secured by bolts 24. At the driving member 22, the power may be divided and transmitted in opposite directions through shafts 25 and 25a, each of which is splined internally to the tubular driving member 22 as indicated at 26.V

From the vshaft 25, the power is transmitted through a steering clutch 2'! to the output shaft I I when said clutch is closed. Additional gearing (not shown) in the lubricantgcontaining compartment I6 is utilized for further speed reduc- Y e centered with openings 29 in the walls I 'I of which but one is shown. Openings 28 carry and center bearing supporting plates 3|- Each plate 3l, secured to its wall I8 by cap-screws 39, contains an opening 32 for accommodating and which is slightly oversize with respect to the shaft 25 or 25'. Roller bearing units 33 are carried upon shoulders 34 in the plates 3I for rotatably supporting the tubular driving member 22 ccaxially with the openings 28 in the compartment separating walls. The bearing units 33 are lubricated by lubricant contained within the gear compartment I4 and some of this lubricant passes between the rollers of such units, but is prevented from leaking into the clutch compartments I5 by annular oil seal devices 35 of any conventional structure. These oil seal devices 35, therefore; cooperate with the tubulal` driving member 22 in preventing the leakage .of the lubricant from the gear compartment I4 outwardly of this compartment through the wall plate openings 32.

The clutch 2l, which may be removed from the housing I5 as a unit is thoroughly described in the aforesaid application, Serial No. 542,143, so that a brief description thereof here will suillce. The driving part of said clutch includes an inner drum 33 onl which there are formed exterior axially extending ribs 3'I which fit into notches (not shown) within the inner peripheries of a'series of friction drive disks 38. A hub 39 for the drum 35 is connected therewith by spoke-like radiating portions 4I, the space between the radiating portions 4I Yaccommodating radiating portions 42 of a pressure plate 43. A coiled spring 44 which tends to maintain the clutch engaged reacts between a portion of the hub 39 and the left end of a spring cup 45 of which the base is connected to the pressure plate 43 by cap-screws 46.. A reaction plate 41 at the left end of the friction rings is secured to the left end of the driving drum 35 by a plurality of circumferentially spaced Capscrews 48 which are anchored in radiallyinwardly projecting bosses 49 on said drum 36. Alternate of the circumferentially spaced bosses 49 are secured to an enlarged 'flanged end 5I of the shaft 25 by cap-screws 52. This is clearly illustrated in Fig, 3. Y

Axial circumferentially spaced ribs 53, on an outer drum 54 of the clutch,y are received in s,

notches (not shown) in the outer periphery of friction driven diskrings 55. The driven drum 54 has an end wall 56 at its outer or right' end which con-j tains coaxial seats 51 and 58 respectively for theV outer periphery of flange 59 on the clutch-driven shaft I I and for a ball bearing unit 6I which pilots the hub 39 ofthe clutch driving member in said endV wall 55. An opening 62 coaxial with the shoulder 58 is sufliciently larger than the portion of the hub 39 therein to accommodate an oil seal member 63 between these parts. Attachment of the driven drum end wall 53 to the clutch-driven shaft I I is accomplished by means of'cap-screws 54 vdistributed circumferentially about the end wall and turned into suitable holes near the edgeV of therllange 59. l f

A ball bearing unit 65 for journaling the driven `shaft Il has its outer race centered with respect to the compartment wall opening 29 by a centering plate 66 ltted intoY such opening and having a shoulder 8'! for said bearing unit. A second shoulder E8 in the centering plate receives an oil seal device 69 which acts with the driven shaft in preventing leakage of Vlubricant from the nal drive compartment I6 into the lubricant-free compartment I5, through the oversizeshaft receiving opening 'Il in said centering plate. AV standard means 'l2A is employed for holding the inner race of the ball bearing unit 65 upon a shaft section 13 and against a shaft shoulder T4,

Normally, as explained hereinabove, the large coiled spring 44 in the clutch maintains the clutch engaged while acting against the hub of the driving drum 36 and pressing the spring cup 45 to the left together with the pressure plate 43, whereby the alternately arranged driving and driven friction/rings 38 and 55 are pressed together in stackedrelation against a reaction plate 41 secured to the left end of the driving drum, 'Thus rotative force from the'clutch driving shaft 25 is transmitted from the driving drum 3BA through the plates 38 arid V55 to the driven drum 54 Vand thence through the driven shaft flange 59 to said driven shaft.Y Release Aof the clutch is effected by manual movement of a throwo-ut bearing unit 15, to the left of theclutch, to the right Y 1 Y2'! to service the same as by the replacementof the friction rings 38 and 55, the mechanic will gain access to the heads of the capscrews52 and 64 through a casing opening 'I8 of Fig. 2 and unscrew these cap-screws respectively from the left end ofthe clutchl driving drum 36 and from the plate 59 on the left end of the clutch driven shaft f II. lOpenings 'I9 (Figs. l and 2) are provided in the clutch driven drum 54 in radia1 registry with the cap-screws 64 sothat the heads of the cap-screws are accessible to a wrench. Subsequent tothe removal of the cap-screws 52 and 84, and the attachment o-f a hoist to the clutch'Z'I, thehshaft 25 will be forced to the left, as viewed in Fig, 2, into abutment with the right end of the shaft 253L so as to provide clearance between the driving and driven shaft flanges or plates 5I and 59, as illustrated in Fig. 2, so that the clutch can be lifted bodily and unitarily from its compartment I5. During these manipulations of the clutch 2l, the oil seal device 69 will prevent the leakage of lubricant from the final drive compartment IE into the lubricant-free clutch compartment I5 and the sealing devices 35 at opposite ends of the tubular driving member 22 together with such tubular member will prevent leakage of lubricant fro-m the gear compartment hi into the clutch compartments. A similar procedure is followed for removing the clutch 2'. (not shown) in the left clutch compartment l5, but, of course, in that procedure the shaft 25a will be moved to the right to abut within the shaft 25 for providing the necessary clearance which facilitates removal of the clutch.

Having thus described a preferred embodiment of the invention with the view of clearly illustrating the same, I claim:

l. In a Vehicle power transmitting apparatus employing a lubricant-free clutch for transmitting power from a lubricatedI gearing; the co.. bination of a vehicle frame housing comprising a lubricant-containing compartment for said gearing and an adjacent lubricant-dry clutch compartment for said clutch, said gear compartment including opposite walls of which one separates said compartments and contains a drive shaft opening, a tubular` driving member journaled in the gear compartment in axial registration with said wall opening and rotatively drivable by said gearing, a clutch driving shaft having a portion telescopically in said tubular member and constrained for rotation therewith, said shaft having a second portion projecting endwise from the tubulai` member and through said wal1 opening into detachable driving connection with said clutch to facilitate endwise retraction of the detached shaft I from the clutch pursuant to projection of the one portion of the shaft further into said tubular member and thereby providing clearance for removal of the clutch from the clutch compartment transversely of said shaft, and sealing means between the tubular driving member and each of said walls to cooperate with said driving member in preventing leakage of lubricant from the gear compartment through said wall opening into the clutch compartment.

2. In a vehicle power transmitting apparatus employing a lubricant-free clutch for transmitting power from a lubricated gearing; the combination of a vehicle frame housing comprising a lubricant-containing compartment for said gearing and an adjacent lubricant-dry clutch compartment for said clutch, said gear compartment including opposite walls of which one separates said compartments and contains a drive shaft opening, coaxially arranged bearings respectively on said compartment walls in axial registry with said wall opening, an internally splined open-ended tubular member extending across the lubricant-containing compartment in journaled relation with said bearings and driven from said gearing, a clutch driving shaft detachably drivingly connected with said clutch and having a splined portion extending endwise from the clutch into telesc-opic meshed relation with the internally splined tubular member and through said wall opening, the telescopic relation of said shaft and tubular member facilitating endwise movement of the shaft from the clutch when detached therefrom to provide clearance for removal of the clutch from its compartment transversely of said shaft, and sealing means between the tubular driving member and each of said walls to cooperate with said driving member in preventing leakage of lubricant from the gear compartment through said wall opening into the clutch compartment.

3. In a vehicle power transmitting apparatus employing lubricant-free clutches for transmitting power from a lubricated gearing; the combination of a vehicle frame housing comprising a lubricant-containing gear compartment for said gearing, lubricant-free clutch compartments on opposite sides of said gear compartment and opposite gear compartment walls separating the gear compartment from said clutch compartments, said walls containing respective coaxially registering openings communicating with the clutch compartments, coaxial bearings respectively on said walls in axial registry with said openings, an open-ended tubular gear-driven driving member journaled in said bearings, said member extending across the gearing compartment in axial registry with said wall openings and being driven b y said gearing, clutch driving shafts having outer end portions respectively detachably connected with said clutches and inner end portions projecting inwardly of said tubular driving member at its ends but spaced axially from one another so either can move endwise when detached from its clutch and thereby provide clearance for removal of its associated clutch transversely thereof, means causing the shafts to rotate with said tubular member while accommodating said endwise movement, and sealing means between said tubular member and each of said walls to cooperate with said member in preventing leakage of lubricant from the gear compartment through said wall openings into the clutch compartments irrespective of clearance between said shafts and said Wall openings.

WILLIAM O BECHMAN. HARRY A. LAND. RUSSEL D. ACTON. 

